Fiber-reinforced resin materials are lightweight and high-strength materials that are gaining increasing use for component fabrication in various applications, including aerospace technologies. Fiber-reinforced resin materials are a composite of woven or nonwoven fiber fabric and a resin matrix. In some cases, fiber-reinforced resin materials may be fabricated as structures having intrinsic stiffening capabilities to further extend the strength and durability of any components formed from these materials. Composite sandwich constructions, for example, may consist of a rigid core between two composite facesheets of fiber-reinforced resin. As one example, U.S. Pat. No. 6,508,910 describes composite sandwich constructions formed from a rigid honeycomb core between two facesheets of fiber fabric pre-impregnated with resin (or “prepreg” fabric). While effective, prepreg architectures such as these may require a complex series of manufacturing steps involving multiple curing cycles and debulking steps. In addition, the cutting of honeycomb-stiffened composite sandwich structures into a number of components may be difficult, as any exposed, cut edges of honeycomb units may reduce product durability or may require additional processing.
Truss structures consist of one or more triangular or trapezoidal truss elements connected at “nodes”. While truss structures are widely appreciated for their ability to provide a rigid framework in construction applications, it remains a challenge to integrate truss elements as stiffening structures in composite sandwich architectures using efficient manufacturing processes. Although a method for manufacturing flexible composite truss structures with a single facesheet has been described in U.S. Pat. No. 8,651,419, the resulting truss structures disclosed therein requires attachment to a rigid support surface such as an airframe to provide a stiffened structure.
Clearly, there is a need for efficient manufacturing methods that provide access to nonflexible, stiffened composite truss structures for various applications.